Modeling heavy ion ionization loss in the MARS15 code

TL;DR

This paper enhances the MARS15 Monte Carlo code by implementing corrections to heavy ion ionization energy loss calculations, accounting for deviations from Bethe theory at various energies and nuclear size effects, validated against experimental data.

Contribution

It introduces new correction models for dE/dx in MARS15, improving accuracy across a wide energy range, especially at low, high, and ultra-relativistic energies.

Findings

Corrections improve agreement with experimental data.

Finite nuclear size effects are significant at ultra-relativistic energies.

Transition energy region shows notable deviations from Bethe theory.

Abstract

The needs of various accelerator and space projects stimulated recent developments to the MARS Monte Carlo code. One of the essential parts of those is heavy ion ionization energy loss. This paper describes an implementation of several corrections to dE/dx in order to take into account the deviations from the Bethe theory at low and high energies as well as the effect of a finite nuclear size at ultra-relativistic energies. Special attention is paid to the transition energy region where the onset of the effect of a finite nuclear size is observed. Comparisons with experimental data and NIST data are presented.